Thiazolidone compounds



Patented Oct. 24, 1950 UNITED STATES PATENT OFFICE THIAZOLIDONE COMPOUNDS John David Kendall and George Frank Duffin,

Ilford, England, assignors t Ilford Limited;

Ilford, England, a British company No Drawing. Application November 9,1948, Se-

rial No. 59,180." In 1947 v 3 Claims. 1 This invention relates to the production of organic compounds which contain a thiazolidone ring and which are useful dyestuff intermediates.

By reacting a compound of the general formulal:

,/NE 1 ,o s.11 r, 15

s N \NH where D is the residue of a five-membered or sixmembered heterocyclic ring system, with chloracetic acid in alkaline solution, there is obtained a compound of the general formula II:

The residue D is preferably a chain of 2 or 3 atoms selected from carbon or nitrogen. All may be carbon atoms or one or two of nitrogen. Thus D may be, for example, the residue of an iminazolyl, dihydroiminazolyl, benziminazolyl, thiouracil, triazole, thiohydantoin or thiotriazolone nucleus.

The following examples, in which the parts'are by weight, serve to illustrate the invention but are not to be regarded as limiting it in any way.

EXAMPLE 1 PREPARATION or 2:3(BENzIMINAzo '1C2 THIAZOLIDONE-l: (a). Preparationoj S-benziminazfoyl (2) thioglycdllic acid NH 0 's 013160 on 15 parts of 2-mercapto benziminazole were dissolved in 4 0 parts of-10% aqueous. sodium hydroxide solution and 9.5 parts of chloracetic;

Great Britain November 10,

acid in 40 'parts of 10 aqueous sodium hydroxide added to it. The solution was heated on: the water-bath for onehour, filtered hot, and'acidifled. with 10 parts of concentrated hydrochloric acid. The product was filtered, and washed with water. M. Pt. 198 C. (d) after recrystallisation from aqueous ethyl alcohol.

(19) Preparation of 2:3(benziminaz0-1'.2'-)- thi'a2oZid0ne-4 (id-0H2 N. 2 parts of S-benziminazoly1-(2)thiogl'ycollic acid, thus prepared, were dissolved in 10 partsof pyridine and 1 part of' acetic anhydride added. The mixture was heated on a water-bath for 10 minutes and then poured into 100 parts of water.

The oil which was pficipitatemystallised on cooling and was recrystallised fronrthykalco them may be EXAMPLE 2 PREPARATION or S-[S-Knro 4-METHYL DIHYDRO- PYRIMIDYL(2)] THIOGLYCOLLIC ACID AND RING- CLOSURE or THE PRODUCT 14.2 parts of methyl thiouracil were dissolved in parts of 10% aqueous sodium hydroxide and 9.5 parts of chloracetic acid in 40 parts of 10% aqueous sodium hydroxide added to it. The solution was heated on the water-bath for half an hour, and acidified hot with 10 parts of concentrated hydrochloric. acid. On cooling, the prodnot-crystallised out. M. Pt. 204 C.

This product, on heating with acetic anhydride as in Example 1, was converted to the corresponding thiazolone compound.

EXAMPLE 3 PREPARATION or S-[ l-Ksro DIHYDROQU'INAZOLYL- (2) ]-THIOGl-YCOLLIC'ACID AND RING-CLOSURE or THE PRODUCT 8.9 parts of Z-thio 4-keto-tetrahydroquinazoline were dissolved in 20 parts of 10% aqueous sodium hydroxide and 4,? parts of monochloracetic acid in 20 parts of 10% aqueous sodium hydroxide were added to it. The solution was warmed onthe water-bath for A of an hour and. then neutralised with 'parts of concentrated hydrochloric acid. The precipitated product was filtered, washed Well with Water and dried. M. Pt. 223? C.

This product, on heating with acetic anhydride as in Example 1, was converted to the corresponding thiazolone compound.

EXAMPLE 4 PREPARATION or 5-METHYL 1 :3 4-TRIAZOLE 2-THI0- GLYCOLLIC ACID AND RING-CLOSURE or THE PROD- UCT 5-methyl Z-mercapto 1:3:4-triazole (2.2 parts by weight) was dissolved in aqueous sodium hydroxide (7.6 parts by volume) and a solution of chloroacetic acid (1.82 parts by weight) in 10% aqueous sodium hydroxide (7.6 parts by volume) was added. The mixture was heated for two hours at 100, filtered hot, cooled and neutralised with concentrated hydrochloric acid (1.9

parts by volume). The product was precipitated as small white needles and was recrystallised from water giving 2.95 parts by Weight, M. Pt.

This product, on heating with acetic anhydride as in Example 1, was converted to the corresponding thiazolone compound.

Whilst in the foregoing examples acetic anhydride has been used as the dehydrating solvent, it, will be understood that other dehydrating solvents can also be employed, though the fatty acid anhydrides, e. g. propionic anhydride or butyric anhydride are the preferred alternatives.

The products of this invention may be converted into dyestuffs, for example by the methods described in our co-pending application Serial No. 59,181, filed November/.9, 1948, corresponding to British appli'ation No. 29,922/47, and where intended for such use frequently need not be isolated from the reaction mixture in which they are formed. As indicated in the said application Serial No. 59,181 ring-closure and dyestuif-formation may be effected as a single operation.

What we claim is:

1. Process for the production of compounds of the general formula:

of more than one and less than four atoms all of which are selected from the group consisting ofcarbon and nitrogen and at least one of which is carbon which comprises subjecting to heating a compound of the general formula:

where D is a chain o-somcoon N where D has the same significance as in the first formula.

2. Process for the production of compounds of the general formula:

which comprises subjecting to heating a compound of the formula:

C-SCHzCO OH in the presence of a monocarboxylic acid anhydride.

4. Process for the of the formula:

production of a compound which comprises subjecting to heating a compound of the general formula:

C 0% \C-SCHZCOOH CON in the presence of a monocarboxylic acid anhydride.

I5 o-somooon y \N where D has the same significance as in the first formula in the presence of acetic anhydride.

6. A compound of the general formula:

and at.

- 1 5 7. A compound of the'general formula:

8. A compound of the general formula:

011, j co-cm JOHN DAVID KENDALL; GEORGE FRANK DUFF'IN.

REFERENCES CITED The following references are of record in the 'file gf this patent:

I 5 FOREIGN PATENTS Number Country Date 7,575 Great Britain 1908 

1. PROCESS FOR THE PRODUCTION OF COMPOUNDS OF THE GENERAL FORMULA:
 6. A COMPOUND OF THE GENERAL FORMULA: 